Fulton County
"Old" Busch (the second one, I guess)
Ballpark in Arlington (new)
But for ktulu7, I've also seen games in Koshien, the Osaka Dome, and Green/Yahoo/Skymark Stadium.
HoDO, you should add Koshien to your list, it's quite an experience. Babe Ruth played there!
Koshien's old school, ivy covered walls, tight seating, right in the middle of the city, almost no parking, you pretty much have to take the train, crazy hard-core fans.
Skymark is big and nice and new and out in a park area (Ichiro's old stadium).
The Osaka Dome is ok. Has little AC vents in the back of the seats, so that is nice. Actually saw a brawl there, which is pretty unusual for Japanese baseball. Also saw our boy Tim Rattay in a SF/Washington pre-season game.